(2x+3y)•(2x-3y)
(7x^2+11y^3)•(7x^2−11y^3)
(12m+2n^2)•(12m−2n^2)
(6a+8b)•(6a−8b)
(m+5n)•(m-5n)
(2a+b)•(2a−b)
(4a+2b)•(4a−2b)
4a^2–b^2
4x^2-9y^2
144m^2–4n^4
49x^4–121y^6
36a^2–64b^2
16a^2–4b^2
m^2-25n^2